Add ability to reference link to other components in docs.

To link to the "typography" component on the "css.html" page from
another component's docs, you can now do
`[link to typography][typography]`
instead of
`[link to typography](/css.html#typography)'.
Add docs for component reference links
Remove rbx for testing

We can add this back in if we start getting error reports. As it stands travis.ci chokes on rbx quite often making it a very noisy test platform.
Update README.md
Move reference link logic to MarkdownRenderer

Signed-off-by: Geoff Pleiss <gpleiss@pivotal.io>
Added '.scss' extension as an alternative to documentation in Sass.
Updated README to link to custom markdown renderer example
Merge pull request #178 from cih/link_to_markdown_renderer_example_in_readme

Updated README to link to custom markdown renderer example
Merge pull request #171 from gpleiss/reference-links

Add support for reference links to other components
Escape title fixes #179
Add JSX support to BlockCodeRenderer

Signed-off-by: Nicole Sullivan <nsullivan@pivotal.io>
Merge branch 'master' of https://github.com/gponsu/hologram into gponsu-master
Merge pull request #181 from a5e/escape-title

Escape title fixes #179
Try sass comments when process scss files

If a scss file doesn't have regular css doc blocks check to see if it
has sass style comments. Additionally, strip leading whitespace on sass
style comments, this fixes issues with haml.
Merge pull request #182 from pmeskers/jsx-templates

Add JSX support to BlockCodeRenderer
Merge pull request #183 from jdcantrell/process-sass-in-scss

Process sass in scss
Update README.md
Fix nil.map call in link_helper
Merge pull request #185 from jdcantrell/intra-link-fix

Fix nil.map call in link_helper
Replace backtick commands with FileUtils calls